Now, stop and think about that.
The areas you speak of are heavily populated with people accustomed to handouts and freebies, are heavily in debt, mainly because they are run by people who hang on to power by promising freebies.
Do you really want to fight to saddle the rest of the country with people who thrive on regulating the productive to death and giving away the rest of what they make to people who are nonproductive or not even supposed to be there?
Besides, there is a large area through to Canada from Texas that isn't Liberal (excluding Minnesota and Illinois) and would side with the South. Most of Flyover Country is conservative, and just about any rural area.
On second thought we may have to fight to let them go. :-)